import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String[] arr = sc.next().split(":");
        int k = sc.nextInt();
        int h = Integer.parseInt(arr[0]);
        int m = Integer.parseInt(arr[1]);
        int allM = h * 60 + m + k;
        System.out.printf("%02d:%02d", allM/60%24, allM%60);
    }
}
